This invention relates to air cushion supported vehicles, and more particularly to marine vessels of such type which are sometimes referred to as surface effect ships ("SES"). Specifically, the invention relates to flexible air cushion seals comprising one or more inflatable bags or "lobes" which move against stationary parts of the vehicle. For example, such seal devices may be used at the stern of a "SES" to extend between the side hulls or skegs of the ship as shown for example in U.S. Pat. No. 3,977,491; or, between air cushion space partitioning keels or skegs or the like for stability purposes, such as shown at 28 in U.S. Pat. No. 3,524,517. Such inflatable seals may also be employed to seal the air cushion at the bow end of the ship; and may comprise either a single bag or "lobe", or pluralities thereof arranged in superposed relation. In any case the seal device is hingedly affixed at its forward end to the hull structure so as to bridge the water/air cushion space beneath the ship, while the major body portion thereof is adapted to float vertically in conformity with the passing of waves or other obstacles under the craft; thereby maintaining the air cushion under the vessel. As the seal moves vertically, such as in response to wave influences thereunder, the opposite ends of the seal slide vertically against the adjacent stationary structures of the vehicle. The purpose of this invention is to eliminate or at least minimize the frictional resistance effects which would otherwise deleteriously wear or tear the fabric of the seal incidental to rubbing contacts between the ends of the seal and the stationary structures of the vehicle. Reference is also made to U.S. Pat. Nos. 3,205,847 and 3,524,517.